Study on the Serotyping and Resistance to erythromycin of Streptococcus pneumoniae in Wuhan

Objective Objective To investigate the serotyping,resistance to erythromycin and resistance phenotypes of Streptococcus pneumoniae in Wuhan.Methods 304 strains of Streptococcus pneumoniae were tested by agar dilution method according to the approved standard of NCCLS to determine their susceptibility to erythromycin,penicillin,various macrolides,and so on.Serotyping of Streptococcus pneumoniae was performed by capsule swelling test.Phenotyping was done by the double-disk diffusion method.Results The percentage of nonsusceptilibity of Streptococcus pneumoniae to erythromycin has reached 84.21%(256/304).cMLSB-phenotype was the prevalent phenotype,the percentage of which was 99.84%(252/256).Only 4 strains were M-phenotype.20 serotypes were involved in 304 strains Streptococcus pneumoniae.The prevalent serotypes were 19,23,6,15 and 14.All penicillin-unsusceptible Streptococcus pneumoniae were included in 6,19 and 23 serotype.Conclusion The rate of erythromycin-nonsusceptilibity Streptococcus pneumoniae was high in Wuhan.Double-disk diffusion method can well detect its phenotype.The prevalent serotypes,especially the multi-resistant strains,were 19,23 and 6 serotype.Pneumococcal Polyvalent Vaccine can well cover these serotypes.